Voltage regulator



May 8, 1951 w. M. MCLAIN VOLTAGE REGULATOR Filed Feb. 19, 1947 INVENTOR WMJcLa/z'n BY (y y ATTORNEYS Patented May 8, 1951 UNITED STATE s PATENT oFFlcE-f" 1 Claim.

This invention relates to a system of generating constant voltage direct current in spite of normal variations in output load. MoreA particularly my invention relates to a circuit includ ing at least one generator, a source of excitation, at least one voltage regulator and a rheostat, all connected to supply and output voltage which is Ysubstantially unaffected by variations in output load.

The generation of current having constant voltage during variations in load is an ever present problem in electrical work. 1t is customary to use a hand operated rheostat in the field of a generator for the purpose of manually readjusting the generated voltage when changes of load of the generator occur. Another common method of controlling voltage is by the use of a carbon pile voltage regulator which may be automatically operated by means of electro-magnetic coils operative responsive to the actualv output voltage after being adjusted manually.

When two generators are to be used in parallel, it has been customary to connect one of the above mentioned control means to each of the generators. The problem of maintaining constant voltage from, and equal sharing of the load by generators connected in parallel is a constant source of irritation to those who operate electrical generators.

This problem is further complicated when it is desired to operate two or more generators in either series or parallel in order to obtain voltages in multiples of the output voltage the generator is designed to deliver. The usefulness of standard equipments is greatly increased by the novel circuits I have invented.

1 am well aware that the individual elements used in my circuits are old. I am also well aware that many schemes have been developed in the art of generating constant voltage electric power, but my invention has many features unrealized in the prior art.

It is, therefore, an object ci my invention to provide a novel circuit for use with generators to supply a constant output voltage during variations oi load of a reasonable amperage.

It is another object of my invention to provide a novel circuit for use with two or more generators to alternately supply one of two or more voltages, each selected voltage being substantially constant in spite of load of a reasonable amperage.

It is a further object of my invention to provide a circuit for use with generators to supply stable 2 voltages which may be manually adjusted to the voltage it is desired to supply.

A still further object of this invention is to provide a motor-generator set having voltage.

regulators connected to the exciter of the generators for controlling the exciter voltage rather than the voltage of the eld of the generators. In this manner and connection arrangement the voltage is controlled at the desired output of the generators.

With the above and other objects in view, my invention consists in the arrangement, combination and details of construction disclosed in the drawings, and specification, and then more par-` ticularly pointed out in the appended claim.

The drawing shows one wiring diagram of an embodiment of this invention.

The purpose of this invention is to provide for varied by an operator within the range of the' generators, either in series or in parallel hookup with the circuit of this invention.

in the drawing there is shown a pair of generators GI and G2 of conventional design with each generator being provided with a iield winding 31, commutating winding 4 I, and output connections 42 and 43, and 44 and 45 respectively. The latter, or output connections 42 and 43, and 44 and 45', are connected to a series parallel switch il, and a common output connector I2 or load terminal means through which the load is connected to the switch II. Between the switch II and the output poles on the connector I2 there are interposed voltmeters I4, suitably connected in the line for indicating the voltage when the generators are either in series or in parallel.

An ammeter as I5 may be suitably connected in the output circuit for indicating the amperage 'being developed. In generator sets of this kind it has been the conventional arrangement to provide voltage regulators between the iield of the generator and the output thereof for maintaining a constant voltage from the generators.

The voltage regulators indicated at Reg. I and Reg. 2 are of the conventional carbon pile type and may by their construction be adjusted to provide an output within the desired range of adjustment. It is an object of this invention to connect the voltage regulator between the exciter for the generators and the output instead of connecting'the regulators directly to the fields of the generators. Also there is provided a variable resistance element or rheostat I6 between the voltage regulators and the exciter for varying and adjusting the output voltage of the exciter Without adjusting the regulators, In this arrangement the generators are connected to the series parallel-switch Il and to the output connection I2 to provide :a wide range of operation at different controlled voltages.

For connecting to the regulators between the exciter E and the negative pole of the output terminal |2 there is provided a connector or :hook-up panel I1 for connecting the regulators and the rheostat I6 to the exciter and to the generators. Wires 2| and 22 from each :of the generators 'is connected from one field connection of each generator to a common terminal 35 of the panel 17 to which is also connected, by lead 24 the negative pole :of Athe exciter The positive Vterminal of the exciter is then connected lto one side of the irheostat lle by wire 20 and the other side of the-rheostat is connected through wire 25 to the positive exciter connection 25 on the panel I1 to which is also connected a A.wire 27 from the carbon Ipile 3.6 of eac-h of the regulators. The otherzlea'd. 2&8 :from the carbon pile of each of the regulators is connected to the other wirev 29 of the eld winding 37' of each of the generators at the .hook-up panel `l Tl.

The coil '39 fof each of the regulators is yconnected also vas at dil to the carbon pile lead 28 connecting directly tothe rleld 37 of each of the generators Gl 'and G2. 'This connection is withi'nv the regulator itself. The other connections 3| and 32 of the coi-ls of the regulators are then connected to the minus pole of the output terminal l2 through connector 34. In this type of connection the voltage regulators `are then raiected by the demand current directly lfrom-'the .negative pole of the output terminal I2 and .in turn vary the .excitation to the eld of both ofthe generators at the same time and will hold the output of the generators constant when they are connected either in series or in parallel and the output of 'the generators may be varied by adjusting the rheostat I6 to the voltage desired.

I do not mean to coni-lne myself to the exact details of construction herein disclosed, .but claim al1 variations falling within the purview of the appended claim.

What I claim is:

An electricity generating system comprising a pair of generators, an exciter, a prime mover connected to said 'generators and said exciter for driving said generators and exciter at substantially constant speed, a series parallel switch having a common output connection for said generators and connected in the output circuit, circuit .connecting means between said exciter and the fields of said generators, said circuit connect- ,ing means `:'rncli-idlng a carbon pile voltage regulator for each of said generators interposed between said exciter and said generators said each carbon pile regulator being operable in response to lthe voltage of 'its respective generator, a -circuit connection from said common youtput *to each ofv said regula-tors 'for adjusting the resistance of 'the carbon pile in relation to the output voltage to 'thereby -vary the strength of the ve'ld of the related generator, and a rheostat in said circuit connecting means between said regulators and said generatc'irs for manually adjusting the strength ofthe generator fields to thereby select the generator output voltage to y-be maintained.

WARREN M. McLAIN.

REFERENCES CIT-ED Country Date Great Britain of 1911 Number Number 

